Homogenizing method and apparatus

ABSTRACT

A method and apparatus for treating flow media at a pumping station wherein an additive is mixed with the flow media at the pumping station and conveyed thereby to a separating station where the conveyed material is subjected to centrifugal force to at least partially separate the material into portions of different specific gravity. A separated portion of the material is removed downstream of the separating station.

United States Patent [1 Hickey, Jr. a

n1] 3,828,929 [451 Aug. 13, 1974 HOMOGENIZING METHOD AND APPARATUS- [76]Inventor: William E. Hickey, Jn, West Hartford, Conn. [22] Filed: 4 Jan.22, 1973 [21] Appl. No.: 325,135

[52] US Cl 210/70, 210/84, 210/219, 2l0/5l2,415/l,'415/116 [51] Int. ClB0ld 21/26 [58] Field of Search 55/17; 210/59, 70, 83,

210/84, 206, 208, 219, 319, 512; 259/19, 21, 22, 23, 24;41.5/l15,116,122 A, DIG. 1,1

[56] References Cited UNITED STATES PATENTS 3,s9s,392 7/1971 Markel..210/s4 3,660,285 5/1972 Markel 210/84 3,743,095 7/1973 Mensing et a1.210/84 Primary Examiner-Charles N. Hart Assistant Examiner,Mukai, RobertG.

Attorney, Agent, or Firm-Prutzman, Hayes, Kalb, ilto I ABSTRACT A methodand apparatus for treating flow media at a pumping'station wherein anadditive is mixed with the flow media at the pumping station andconveyed thereby to a separating station where the conveyed material issubjected to centrifugal force to at least partially separate thematerial into portions of different specific gravity. A separatedportion of the material is removed downstream of the separating station.

21 Claims, 6 Drawing Figures PATENIED I 31974 SHEEI 2 BF 2 R E L L E P MSTAT ON PUM NG HOMOGENIZING METHOD AND APPARATUS This inventiongenerally relates to apparatus and processes for material handling andparticularly concerns an apparatus and method for homogenously mixinglarge volumes of different material and thereafter separating andremoving at least a portion of the homo'genous mixture or composite ofthe mixed materials'.

A primary object of this invention is to provide a new and improvedapparatus particularly suited for high speed operations and high volumecapacities to effect at a pumping station efficient mixing of flow mediaand a selected additive in a highly diffused separable homogenouscomposite and to thereafter separate a portion of the compositedownstream of the pumping station, for removal from the remainder of thecomposite.

Another object of this invention is to provide a new and improvedapparatus of the type described of significantly simplified constructionparticularly suited for use in a variety of applications havingrequirements for high volume processes on an uninterrupted flow basisundereffectively controlled conditions.

A further object of this invention is to provide such a new and improvedapparatus for processing composites of fluids as well as solids or fluidand solid admix tures in effectively controlled proportions.

Another primary object of this invention is to provide a new andimproved method of treating a material prior to conveying the treatedmaterial downstream for separation of at least a portion of the treatedmaterial and which is particularly suited for applications having highenergy input and high operating speed requirements.

Another object of this invention is to provide such a new and improvedmethod particularly suited for continuous high volume industrialprocesses.

A further object of this invention is to provide such a new and improvedmethod which effectively controls input and output of materials to bephysically mixed in homogenous proportions and also ensures a smoothcontinuous process in physically conveying the homogenous composite to aseparating station on a continuous feed basis for selective removal of aportion of the conveyed composite.

A still further object of this invention is to provide such a methodwhich may be used in a variety of different applications for handlingdifferent combinations of fluids or combinations of solids as well ascombinations of fluids and solids and which provides for efficient andeconomical separation of a selected portion of the composite withoutrequiring complicated and expensive chemical processing equipment.

Other objects will be in part obvious and in part pointed out in moredetail hereinafter.

The invention accordingly comprises the several steps and the relationof one .or more of such steps with respect to each of the others and theapparatus possessing the features, properties and the relation ofelements which are exemplified in the following detailed disclosurewhich also sets forth an illustrative embodiment of the apparatusemployed in this invention indicative of the way in which the principleof this invention is employed.

In the drawings:

FIG. 1 is a side view, partly broken away and partly in section, of anaxial flow unit at a pumping station incorporated in this invention;

FIG. 2 is a fragmentary schematic diagram, partly in section, showingcomponents of a processing system incorporating the method and apparatusof this invention;

FIG. 3 is an axial end view showing a blade profile projection of theaxial flow unit used at the pumping station of the processing system ofFIG. 2;

. FIG. 4 is an axial end view showing a blade profile projection of anaxial flow unit used at a separating station of the processing system ofFIG. 2;

FIG. 5 is a side view, partly broken away and partly in section, showingan additive collection ring which is externally mounted on a rotor ofthe axial flow unit of FIG. 1; and

FIG. 6 is a diagrammatic flow profile characteristic of the axial flowtype unit used in the illustrated embodiment of this invention.

Referring to the drawings in detail wherein a preferred embodiment ofthis invention is shown for illustrative purposes, unit 10 is an axialflow pump which may be either a single stage unit or multiple stage unitwith each. unit having a cylindrical rotor 12 which is fragmentarilyshown in half-section in FIG. 1. Impeller blades such as the one shownat 14 in FIG. 1 provide propulsion for material in a flow passagewaythrough rotor 12 in the axial direction of arrow 16 from an inlet end ofthe unit, not shown, to an outlet end of the unit at the left-hand sideof rotor 12 in FIG. 1. In FIG. 3, three equally spaced helical impellerblades 14 are shown providing an axially unobstructed flow passagewaythrough rotor 12 although it is to be understood that this invention isnot limited to such specific impeller arrangement. Rotor 12 is shownmounted for rotation within a cylindrical chamber of a housing generallydesignated 18. Units of this general type are normally powered andrequire a suitable power source such as a motor, not shown, for rotatingan input shaft, not shown, drivingly connected to a drive gear 20 shownin mesh with driven ring gear 22 secured by bolts such as at 24 to anoutside wall of the rotor 12. As fully described in Harvey E. Richterscopending US. Pat. application Ser. No. 236,433 filed Mar. 20, 1972,entitled Improved Mechanical Seal, and assigned to the assignee of thisinvention, housing 18 provides mountings for drive shaft bearings 26within housing gear casing 28 and also for bearings such as at 30supporting the rotor 12 for rotation about a rotational axis generallydesignated X-X. The above referenced patent application more fullydescribes the housing and rotor construction of that embodiment shown inFIG. 1, and the subject matter of that application is incorporatedherein by reference.

It should be noted that annular end mounting flanges such as 34 aresuitably secured by a machine bolt, not shown, to each axial end of thehousing 18 to maintain a seal assembly such as at 36 in operativeassociation with the rotor 12 within enlarged annular chambers as at 38which will be understood to circumferentially extend around the axialend portions of rotor 12. The illustrated left-hand axial end of rotor12 is provided with a seal mating ring 40 shown secured on the lefthandportion of rotor 12 (FIG. 1), and a pair of 0 ring seals 42, 42 will beunderstood to extend continuously around the outer periphery of rotor 12with a desired radial interference-fit to provide a fluid-tight seal,with each ring seal 42, 42 being received within recessed grooves 44, 44in seal mating ring 40. Seal mating ring 40 is drivingly connected tothe rotor by removable retaining pins such as shown at 46, and pins46cooperate with a retaining ring 48 to releasably secure the sealassembly 36 in a position on the rotor 12. Undesired passage of oil,water, and other contaminants into. chamber 38 is controlled by a pairof ring seal subassemblies 50, 52 secured to housing 18 and presentingoppositely facing radial surfaces for sealing engagement with anadjacent side of seal mating ring A controlled homogenous mixing processfor various combinations of fluids or solids or fluid and solidcomposites is provided in an apparatus particularly suited forcontinuous high volume operation. As described in Harvey E. Richterscopending US. Pat. application Ser. No. 280,675 filed Aug. 14, 1972,entitled Additive Diffusor and assigned to the assignee of thisinvention, an additive diffusor 53 is provided, preferably in eachimpeller blade 14, to disperse a selected additive in controlledproportions relative to the flow media passing through the rotor 12.Diffusor 53 may be employed in different ways, e.g., in dispersing solidparticulate matter into a sludge of flowable material passing throughrotor 12, or in mixing different fluids such as a gaseous additive to behoinogenously mixed together with a liquid media in the passageway ofrotor 12. While it is intended that each of the impeller blades 14 arepreferably provided with an additive diffusor, for purposes ofexplanation, it will be sufficient to describe only one shown for blade14 as illustrated in FIG. 1.

In the specifically illustrated embodiment, rotor impeller blade 14(FIG. 1) extends from an inside rotor wall 54 (along line 56) to providea free edge 58 on blade 14 disposed radially inwardly of wall 54 suchthat blade 14, when rotated, acts as a screw propeller to propel flowmedia through the rotor 12..Blade 14 is preferably helical in shape andincludes a trailing downstream edge 60 which is directed radiallyoutwardly from an apex 62 of the blade 14 toward inside rotor wall 54.

This blunt downstream trailing edge 60 of impeller blade 14 provides forcavitation in the region of the flow passageway immediately adjacent theedge 60 at a predetermined rotor speed, and a plurality of dispersionoutlets are shown such as at 64 formed in the downstream trailing edgesurface of the impeller blade. Each dispersion outlet 64 is connected byan individual passageway 66 to a common internal manifold 68 formedinside blade 14 which leads toward its root portion where the blade 14merges with the inside wall 56 of rotor 12. At the rotor of the blade14, a valve body 70 is shown defining a valve chamber 72. Chamber-72communicates with manifold 68 through an outlet port 74 and connects tothe chamber 38 of housing 18 via an inlet port 76 in valve body 70 and acommunicating opening 78 in the seal mating ring 40.

Chamber 38 may conveniently serve as an additive accumulator chamber forsupplying various selected additives to the flow passageway of rotor 12.For controlling additive flow through the above described passage meansbetween chamber 38 and the outlets 64, a ball check valve member 80 isreceived in the valve chamber 72 and is biased by a spring 82 radiallyinwardly against a valve seat surrounding outlet port 74 and into itsillustrated normally closed flow control position.

Servicing the additive diffusors for each impeller blade 14 is a commonadditive collection ring 84 secured by any suitable means, not shown, tocircumferentially extend about the seal mating ring 40. Upon rotation ofrotor 12, additive within the accumulator chamber 38 will be collectedfrom chamber 38 by raised vanes 86 (best seen in FIG. 6) formed oncollection ring 84 with openings facing in the direction of rotation.The vanes 86 positively direct the additive into a common accumulatorgroove 88, which will be understood to circumferentially extend aroundthe outer periphery of the seal mating ring 40, and through each of theplurality of openings such as illustrated at 78 in the seal mating ring40 and into each valve chamber 72 of the impeller blades 14. If desired,a suitable coupling 90 to a supply conduit 92 may be secured to thehousing 18 for supplying additive (through a connecting passage thereinsuch as at 94) into the accumulator chamber 38. The illustratedarrangement obviously may be varied and tailored to' different types ofadditives being supplied, depending on whether the additive is a gas,liquid or solid and the nature of the solid additive if such is beingused in the application of this invention. a

The cavitation region behind each impeller blade 14 provides a suctionforce at a predetermined rotational speed of the rotor l2 as flow mediapasses over opposite sides of the blades 14, and centifugal forcedeveloped by rotor rotation causes the ball check valve member toautomatically move radially outwardly against the bias of its spring 82to permit additive in chamber 38 to be collected and positively directedby the additive collection ring 84 into the common manifold 68 andthrough the connecting individual passages 66 to each of the dispersionoutlets 64.

By such construction, uniform distribution of additive through each ballcheck valve of the respective impeller blades 14 and into their manifold68 is provided to permit the additive to be forced out the dispersionoutlets 64 under suction force and dispersed into the flow passageway inthe rotor in a fan-like continuous sweeping action, providing a veryeffective spiralling turbulent mixing of the additive'with the flowmedia. As the rotor 12 slows down at shut-off the cavitation effect isreduced to minimize the pressure differential between the chamber 38 andthe dispersion outlets, and the centrifugal force is diminished wherebythe spring 82 automatically returns its ball check valve member 80 intonormally closed flow control position. Any undesired accumulation offlow media within the accumulator chamber 38 is effectively preventedvto protect the integrity of the additive composition in addition toprotecting the seal area about the outer periphery of the rotor.

Turning now to the system incorporating the processing method andapparatus of this invention for, mixing different materials into ahomogenous separable composite of the additive and the flow media andthereafter separating and removing at least a portion of the compositeunder high operating speed and high volume throughput conditions, thelead and pitch of each of the described impeller blades 14 isselectively dimensioned and contoured such that a vigorous propellingeffect is produced by the pumping unit 10 to mix the additive with theflow media received, e.g., from supply line 98 (FIG. 2) within thepumping station 100 and to additionally drive the resulting homogenouscomposite downstream through a connecting pipeline 102 in a smoothpowerful thrusting flow toward a separating station generally designated104.

By virtue of the disclosedconstruction, the total system is particularlysuited to extract selected specific gravity masses from the total matterbeing mixed and transferred. An example would be in providing aneffective solution to separating out a relatively heavy precipitant in ahigh volume chemical process resulting from the mixing of a selectedadditive and flow media at the pumping station 100. In short, the fluidflow unit at the upstream pumping station 100 supplies sufficientkinetic energy required to transport the total mass through the entiresystem while the secondary or downstream fluid flow unit at theseparating station 104 provides sufficient centrifugal energy requiredto effectively arrange different specific gravity elements of the totalmass in a manner proportional to the radius of the connected pipeline.

To effect efficient separation of the composite materials whileoperating at speeds and throughput volumes tions of the materials to beprocessed, the separating type similar to unit 10. That is, the units ofboth-the pumping and separating stations 100 and 104 exhibit similarflow profiles with axial velocity output (V,,) characteristics ofgenerally proportional magnitude and direction relative to theirrespective pipeline cross sections as diagrammatically represented inFIG. 6. In the specifically illustrated embodiment of this invention,unit 10 is an axial flow device as previously described and theseparating station unit also is preferably an axial flow device having ablade projection such as illustrated in FIG. 4 wherein the impellerblades 106 at the separating station 104 are of a modified lead andpitch arrangement in relation to blades 14 0f the pumping station unitshown in FIG. 3 but without any additive diffusors being provided in theimpeller blades 106. The impeller blade construction of the separatingstation unit is designed to provide an axial flowpumping rate throughthe pipeline system less than that of unit 10 of the pumping stationwhile imparting a significantly greater centrifugal force'on theconveyed mixture upon its being received within the flow passageway ofthe separating station 104 whereby its blades 106 each act on asubstantial length and perimetrical depth of the column of mixtureconveyed to the separating station 104.

To facilitate extraction of a desired specific gravity mass or portionof the conveyed mixture, a plenum chamber 108 is shown intermediate thepumping and separating stations 100 and 104 in communication with theinterconnecting pipeline 102. Plenum chamber 108 is designed to provideappropriate low and high pressure regions upstream of the separatingstation 104 to stabilize high throughput volumes of mixed materialsconveyed by the pumping station and to make the system independent ofnormally encountered pressure fluctuations. The disclosed system istotally independent and needs no other sundry mechanisms, vacuumtechniques and other conventional equipment normally masses involvedinto separate portions based on their specific gravities.

More specifically, variation in specific gravities of solids, liquidsand gases which may be transported through pipeline 102 and the vorticalmotion which is imparted by unit 10 to the flow media causes it to bearranged in a predictable manner inside pipeline 102 due to the velocitydiagram (FIG. 6) and flow profile of unit 10 at the pumping stationwhereby the location of the different specific gravity massed beingdriven through pipeline 102 is a direct function of the radius of thepipeline 102 with theheavier specific gravity matter being arrangedalong the outer radial areas.

Assume that shaded section A represents a volume of mass transportedthrough a completely filled pipeline 102 in one revolution of pump rotor12 under given steady flow conditions wherein the downstreambackpressure and rotational rotor speed are relatively constant. Tostabilize the core of the conveyed mixture and thereby facilitate itsextraction in a manner related to its different specific gravity masses,the volume of annular section B of plenum chamber 108 is designed largerthan the volume of section A and plenum section C'is somewhat smaller involume than section B and in coaxial alignment therewith to provide ahigh pressure zone, represented by section B, within plenum chamber 108surrounding a relatively low pressure zone (section C) wherein lowerspecific gravitymasses are forced downstream along the central portionof pipeline 102 through its plenum chamber 108.

By such plenum design, pressure variations across a section of pipeline102 are significantly more uniform since backpressure increase due tothe change in direction of mass flow is absorbed in plenum chambersection B and variationsin pressures due to the mass separating orextraction effect of plenum chamber 108 are also dampened in its largevolume section B. As mentioned, plenum chamber 108 additionally servesto augmer t the separation of masses of different specific gravitieswhich actually takes place in a transitional region between sectionlines D-D and E-E. In this transitional region, line pressure increasesradially and provides a compressed cone effect such as depicted bybroken lines at 109, allowing lower backpressures along the centerportion of chamber 108 while the change in velocity direction asindicated by lines 111 and reduction in its axial magnitude createshigher pressures along the outer perimetrical depth of the diverginginput end of chamber 108 to stabilize the separation process bysurrounding the centrally arranged lighter specific gravity massespassing through chamber 108 within the described surrounding highpressure zone (section B) while also allowing the higher specificgravity masses with their relatively high kinetic energy and centrifugalvelocities to easily pass around the outside of cone 109 into thesurrounding high pressure zone of chamber 108. If desired, an annularmanifold, not shown, may be used in the transitional region of chamber108 to promote separation of the different specific gravity masses. Itis to be understood that the described system may be designed forlaminar flow of the lower specific gravity masses through the center ofplenum chamber 108 thereby significantly stabilizing the core of themass flow. While the diverging input end of chamber 108 may reduce thecritical Reynolds number, practically all cases of fluid flow throughthe surrounding high pressure outer zone of chamber 108 will be in theturbulent-flow region.

Accordingly, the flow media to be treated is continuously passed fromsupply line 98 through the pumping station 100 and a supply of aselected additive is uninterruptedly diffused into the flow passagewayduring rotor rotation to effect a homogenous mixing. The pumping actionof the pumping station unit is augmented by the propulsive effect of theseparating station unit to physically convey the mixture throughpipeline 102 and its plenum chamber 108 to the separating station unit.lts impeller blades 106 are driven at a sufficient speed tocentrifugally force that portion of the mixture of maximum specificgravity radially outwardly toward the inside wall 113 of the separatingstation rotor 110 (preferably having an inside diameter equal to that ofplenum chamber 108). The centrifugate assumes a generally uniformcylindrically profiled form which is simultaneously driven downstreamalong the inside wall 112 of a connecting pipeline 114 by the propellingeffect of the separating station unit. The passageway in pipeline 114 ispreferably uniform and coaxially aligned and coextensive with the flowpassageway of the rotor 110, and the heavier portion of the centrifugedmixture is axially forced downstream into a zone of pipeline 114established by its maximum inside diameter and a radially inwardlydisposed outside surface of a concentric conduit 116 of reduced diameterwhich will be understood to be mounted in coaxial downstream relation tothe flow passageway extending through the separating station rotor 110.Lighter specific gravity. portions of the centrifuged mixtureaccordingly will be forced into the reduced conduit 116 centrallydisposed within pipeline 114, and the centrifugate may be readilyremoved at least in part by the continued pumping action of theseparating station unit forcing the higher specific gravity portion intoa tributary conduit shown at 118 for suitable disposition furtherdownstream.

In summary, it will be evident that the apparatus and method of thisinvention is particularly suited for a variety of different industrialprocesses. For example, where it is critical to obtain a change of stateof chemicals being processed such as a liquid and a gas to form a liquidof different physical and chemical properties and a solid precipitant,e.g., or to form different liquids of different specific gravity, theapparatus and method of this invention is particularly suited to achievesuch purposes. The disclosed apparatus and method may achieve suchpurposes in a controlled manner. The speed of rotation of the pumpingand separating station units are designed to be independently andselectively controlled to correspondingly regulate the process, theinput of diffusable additive, the degree of centrifugal force to beapplied to the conveyed homogenous mix-- ture, the desired time delayfor any desired reaction, the desired time delay for effecting flowbetween the pumping andseparating stations, etc. The described theprimary separating force while augmenting the axial pumping force of thepumping station unit and forcing'the separated mixture portionsdownstream for removal. The method of this invention supplies its ownmotion transmission and flow regulation without relying on any weirs andwithout any gravity or vacuum methodsof separating or drawing off gases,liquids or solids into separate passageways. In addition, if theinput'chemicals vary somewhat in consistency, the combination of thedisclosed axial flow units of similar type effectively minimize suchvariations to a significant extent by effective mixing andhomogenization of all elements at the pumping station thereby ensuringuninterrupted flow without substantial variations in construction of thecomponents required provides a significantly simplified system whereinthe pumping station unit provides the mixing action and also the basicpumping force. The plenum chamber 108 augments the extraction action ofthe separating station while further minimizing and accommodating linepressure fluctuations, The separating station unit provides proportionor the type of chemicals in a continuous process that is not believed tobe normally feasible by the application of conventional teachings.

As will be apparent to persons skilled in the art, variousmodifications, adaptations and variations of the foregoing specificdisclosure can be made without departing from the teachings of thepresent invention.

I claim:

1. A method of treating material at a pumping station of a pipelinesystem and withdrawing a portion of the treated material downstream froma separating station of the pipeline system comprising the steps ofsupplying the material to be treated to the pumping station, supplying adiffusible additive to the material at the pumping station, mixing thematerial and the additive at.the pumping station to form a homogenousseparable composite of the material and the additive by applyingvortical motion to the composite by an axial flow pump at the pumpingstation, conveying the homogenous composite in the pipeline system fromthe pumping station to the separating station, stabilizing the flow ofthe conveyed composite upstream of the separating station by passing itthrough a plenum chamber having a diverging inlet whereby a core portionof the composite being conveyed in the pipeline system to the separatingstation is surrounded by a generally uniform cylindrical profiledcentrifugate of the conveyed composite under high pressure relative tothat of the core portion of the conveyed composite, applying acentrifugal force to the conveyed composite at the separating station toat least partially separate the composite into portions of differentspecific gravity, and removing a separated portion of the composite.

2. The method of claim 1 wherein the conveyed composite is a homogenousadmixture of fluids.

3. The method of claim .1 wherein the conveyed composite is a homogenousmixture of solids.

4. The method of claim 1 wherein the conveyed composite is a homogenousfluid and solid mixture.

5. The method of. claim 1 wherein the conveying of the composite isprovided by a pumping action of the pumping station.

6. The method of claim 1 wherein the application of centrifugal force atthe separating station is provided by an axial flow pump having agenerally cylindrical rotor with impeller means mounted on andprojecting generally radially inwardly from an inside wall of the rotor.

7. The method of claim 6 wherein the centrifugal force is applied byrotating the conveyed composite in the axial flow pump at a speedsufficient to force the centrifugate into a generally uniformcylindrically profiled form, and wherein the removing of a separatedportion of the mixture is effected by pumping its separated portionsrespectively through concentric conduits disposed downstream of theseparating station in coaxial alignment with the generally cylindricalpump rotor.

8. The method of claim 6 wherein the mixing of the material and theadditive at the pumping station is provided by a second axial flow pumphaving a cylindrical rotor with impeller means mounted on an inside wallof the rotor, and wherein the conveying of the composite of the materialand the additive is jointly provided by the first and second axial flowpumps through a coaxial interconnecting pipeline.

9. The method of claim 8 wherein separation of the composite and removalof a separated portion thereof is controlled by maintaining the axialflow pump of the separating station at a pumping rate less than that ofthe axial flow pump of the pumping station.

10. The method of claim 1 wherein the mixing of the material and theadditive at the pumping station is provided by an axial flow pump havinga generally cylindrical rotor with impeller means mounted on andprojecting generally radially inwardly from an inside wall of the rotor.

11. The method of claim 10 further including the step of regulatingadditive input by controlling the rota tional speed of the pump rotorduring mixing of the material and the additive at the pumping station.

12. The method of claim 10 wherein the material to be treated iscontinuously suppliedto the pumping station, and wherein the diffusableadditive is continuously supplied to the pumping station through adispersion outlet in the impeller means of the axial flow pump.

13. A system for treating flow media with an additive.

comprising a conveying pipeline, a first axial flow pump unit in thepipeline conveying system, a second axial flow pump unit in the pipelineconveying system in downstream communication with the first unit, and aplenum chamber between said first and second units, the first unitincluding additive diffusing means for mixing an additive with flowmedia supplied to the first unit and a cylindrical rotor having an axialflow passageway therethrough with an impeller blade arrangement locatedin the passageway for effecting a turbulent mixing action to provide ahomogenous separable composite of the flow media and the additive, saidplenum chamber having a conical inlet extending in radially divergingconcentric relation to the adjacent upstream flow passageway of thepipeline conveying system, and an outlet connected to the rotor of thesecond unit for stabilizing the flow of the composite input to the sec-0nd unit, the second unit including a cylindrical rotor having an axialflow passageway therethrough with an impeller bladearrangement forcentrifuging the stabilized composite received from the plenum chamberto at least partially separate the centrifugate for removal from theremainder of the centrifuged composite and means for removing saidseparated centrifugate from the remainder of the composite.

14. The apparatus of claim 13 wherein the rotors of the first and secondaxial flow units are independently controlled.

15. The apparatus of claim 13 wherein the first axial flow unit has apumping rate greater than that of the second axial flow unit.

16. The apparatus of claim 13 wherein the plenum chamber includes acentral core section having a crosssectional area which is approximatelyequal but slightly less than the cross-sectional area of the adjacentupstream flow passageway of the pipeline conveying system, the remainingportion of the plenum chamber surrounding its central core sectionhaving a crosssectional area which is greater than that of the adjacentupstream flow passageway of thepipeline conveying system.

17. The apparatus of claim 13 wherein the outlet of the plenum chamberand the rotor of the second unit are of generally uniform diameter.

18. The apparatus of claim 13 wherein the additive diffusing meansincludes an additive supply source, a dispersion outlet in an impellerblade of the first unit rotor, passage means connecting .the additivesupply source with the dispersion outlet, and a valve control in thepassage means and carried in the first rotor for controlling additiveflow, the valve control means being movable from a normally closed flowcontrol position to an open position responsive to application ofcentrifugal force upon rotor rotation.

19. The apparatus of claim 18 wherein regulation of the valve control iseffected by variation in the centrifugal force applied by the firstaxial flow unit rotor to automatically proportion additive diffusion tothe flow media being pumped by the first unit.

20. The apparatus of claim 18 wherein said impeller blade includes adownstream trailing edge surface, and wherein the dispersion outlet isformed in said downstream trailing edge surface adjacent a cavitationregion created downstream thereof in the flow passageway upon rotorrotation.

21. The apparatus of claim 13 wherein the rotors of the first and secondaxial flow units and the plenum chamber are in coaxial alignment.

2. The method of claim 1 wherein the conveyed composite is a homogenousadmixture of fluids.
 3. The method of claim 1 wherein the conveyedcomposite is a homogenous mixture of solids.
 4. The method of claim 1wherein the conveyed composite is a homogenous fluid and solid mixture.5. The method of claim 1 wherein the conveying of the composite isprovided by a pumping action of the pumping station.
 6. The method ofclaim 1 wherein the application of centrifugal force at the separatingstation is provided by an axial flow pump having a generally cylindricalrotor with impeller means mounted on and projecting generally radiallyinwardly from an inside wall of the rotor.
 7. The method of claim 6wherein the centrifugal force is applied by rotating the conveyedcomposite in the axial flow pump at a speed sufficient to force thecentrifugate into a generally uniform cylindrically profiled form, andwherein the removing of a separated portion of the mixture is effectedby pumping its separated portions respectively through concentricconduits disposed downstream of the separating station in coaxialalignment with the generally cylindrical pump rotor.
 8. The method ofclaim 6 wherein the mixing of the material and the additive at thepumping station is provided by a second axial flow pump having acylindrical rotor with impeller means mounted on an inside wall of therotor, and wherein the conveying of the composite of the material andthe additive is jointly provided by the first and second axial flowpumps through a coaxial interconnecting pipeline.
 9. The method of claim8 wherein separation of the composite and removal of a separated portionthereof is controlled by maintaining the axial flow pump of theseparating station at a pumping rate less than that of the axial flowpump of the pumping station.
 10. The method of claim 1 wherein themixing of the material and the additive at the pumping station isprovided by an axial flow pump having a generally cylindrical rotor withimpeller means mounted on and projecting generally radially inwardlyfrom an inside wall of the rotor.
 11. The method of claim 10 furtherincluding the step of regulating additive input by controlling therotational speed of the pump rotor during mixing of the material and theadditive at the pumping station.
 12. The method of claim 10 wherein thematerial to be treated is continuously supplied to the pumping station,and wherein the diffusable additive is continuously supplied to thepumping station through a dispersion outlet in the impeller means of theaxial flow pump.
 13. A system for treating flow media with an additivecomprising a conveying pipeline, a first axial flow pump unit in thepipeline conveying system, a second axial flow pump unit in the pipelineconveying system in downstream communication with the first unit, and aplenum chamber between said first and second units, the first unitincluding additive diffusing means for mixing an additive with flowmedia supplied to the first unit and a cylindrical rotor having an axialflow passageway therethrough with an impeller blade arrangement locatedin the passageway for effecting a turbulent mixing action to provide ahomogenous separable composite of the flow media and the additive, saidplenum chamber having a conical inlet extending in radially divergingconcentric relation to the adjacent upstream flow passageway of thepipeline conveying system, and an outlet connected to the rotor of thesecond unit for stabilizing the flow of the composite input to thesecond unit, the second unit including a cylindrical rotor having anaxial flow passageway therethrough with an impeller blade arrangementfor centrifuging the stabilized composite received from the plenumchamber to at least partially separate the centrifugate for removal fromthe remainder of the centrifuged composite and means for removing saidseparated centrifugate from the remainder of the composite.
 14. Theapparatus of claim 13 wherein the rotors of the first and second axialflow units are independently controlled.
 15. The apparatus of claim 13wherein the first axial flow unit has a pumping rate greater than thatof the second axial flow unit.
 16. The apparatus of claim 13 wherein theplenum chamber includes a central core section having a cross-sectionalarea which is approximately equal but slightly less than thecross-sectional area of the adjacent upstream flow passagewAy of thepipeline conveying system, the remaining portion of the plenum chambersurrounding its central core section having a cross-sectional area whichis greater than that of the adjacent upstream flow passageway of thepipeline conveying system.
 17. The apparatus of claim 13 wherein theoutlet of the plenum chamber and the rotor of the second unit are ofgenerally uniform diameter.
 18. The apparatus of claim 13 wherein theadditive diffusing means includes an additive supply source, adispersion outlet in an impeller blade of the first unit rotor, passagemeans connecting the additive supply source with the dispersion outlet,and a valve control in the passage means and carried in the first rotorfor controlling additive flow, the valve control means being movablefrom a normally closed flow control position to an open positionresponsive to application of centrifugal force upon rotor rotation. 19.The apparatus of claim 18 wherein regulation of the valve control iseffected by variation in the centrifugal force applied by the firstaxial flow unit rotor to automatically proportion additive diffusion tothe flow media being pumped by the first unit.
 20. The apparatus ofclaim 18 wherein said impeller blade includes a downstream trailing edgesurface, and wherein the dispersion outlet is formed in said downstreamtrailing edge surface adjacent a cavitation region created downstreamthereof in the flow passageway upon rotor rotation.
 21. The apparatus ofclaim 13 wherein the rotors of the first and second axial flow units andthe plenum chamber are in coaxial alignment.